Hack in pure-Python PP rules
Add GRIB support and fix remaining issues/tests.
Remove obsolete methods
Remove quickplot unit label for time reference coordinates. Closes #615.

1D plots in quickplot omit the units part of the axis label when the
coordinate it represents is given as a time reference, and hence will
have been converted to an absolute date/time.
Merge pull request #616 from ajdawson/quickplot-time-units

Remove quickplot unit label for time reference coordinates. Closes #615.
Delete temp_test_output.txt

Fix to #462.
Convert post-item documentation to pre-item #: form
Merge pull request #618 from rhattersley/docstrings

Convert post-item documentation to pre-item #: form
Merge pull request #611 from rhattersley/rulegen

PP/GRIB load rules as a function
PEP 8 iris._cube_coord_common
PEP 8 iris.fileformats.ff
Merge pull request #621 from rhattersley/pep8-ff

PEP 8 iris.fileformats.ff
Merge pull request #620 from rhattersley/pep8-cube_coord_common

PEP 8 iris._cube_coord_common
ENH: Allow cube slicing by dimension index

Currently only coordinates can be used to slice a given cube.  Since
coordinates are not allways associated with dimensions of a cube, the
ability to specify dimension and or mix of coordinate and dimension is
added here to facilitate use.